Whether medical oxygen and nitrous oxide can be treated as medicines for the purpose of levy of tax under the Kerala General Sales Tax Act, 1963 (for short, “the Act”) is the question involved in this case.

2. The assessee is the revision-petitioner. State is the respondent. The assessment year is 1987-88. The assessee is engaged in the manufacture and sale of medical oxygen and nitrous oxide. In the assessment for the year 1987-88 the assessee contended that the said two items are liable to be assessed at the rate of 5 per cent under the Notification G.O. (Rt.) No.242/84/TD. The assessment was originally completed by assessing “medical oxygen” at 5 per cent under the above notification and “nitrous oxide” at 6 percent under entry No.85 of the First Schedule to the Act as it stood at the relevant time. However, the said assessment was reopened under section 19 of the Act on the ground that “medical oxygen” and “nitrous oxide” are liable to be assessed at higher rates. In spite of the objection taken by the assessee, the assessing authority passed a revised assessment order dated July 22, 1992 (annexure A) under which “medical oxygen” was assessed at the rate applicable t